Fiberboard carton



J. LARRIMORE ET AL FIBERBOARD CARTON Nov. 16, 1943..

Filed 001;. 10, 1942 I Patented Nov. 16,1943 I 2,334,634 FlBERBOARD CARTON James Larrimore, Bellerosc, Otto L. Scheller, Little Neck, and StanleyM. Jackson, Glen Head,

N. Y., assignors to Loose-Wiles Biscuit Compa'ny, Long Island City, N. Y., a corporation of New York Application October 10, 1942, Serial No. 461,612 2 Claims. 01. eta-3.1)

, This invention is a fiber-board carton suited for long-distance shipment of foodstuffs and the like, and capable of submersion in water for long periods without leakage, and which can be inexpensively and rapidly produced. Prior to this war the only durable shipping package, adequately waterproof, has been of tin-plate with soldered seams. plate is not available for this Purpose, and although'the principle of waterproofing containers is of course well understood, no fiber-board substitute has heretofore been found capable -of.meeting the requirements, which are severe.

It is required, for instance, that such substitute shall be sufliciently durable as respects its waterproofness as not to become leaky as the result of the deforming pressures incident to being stacked high for storage or for shipment in railway cars or in the holds of vessels, or by the effect of extreme temperatures, ranging from as cold as -l F. to as hot as 135 F., and such as may occur in ships holds in tropical climates;

Under present conditions tinthey must remain securely waterproof when stacked out of doors for long periods and when submerged in waterfor at least two days so that they can lie-unloaded from supply vessels directly into the water and allowed to float ashore or be gatheredby shore boats.

The fiber-board carton illustrating. this invention has been found acceptable and to meet all out of solid fiber-board of a kind containing in its composition suflicient sizing ingredient (rosin and alum, or the like) to make it impervious to water for at least several days of submersion. Such fiber-board is a commercial product and inexpensive.- For normal carton size of say, 9 x 12 x 15, it should caliper about .09", but there is no-limltation to the particular grade or weight.

The body is formed from a pre-cutblank with flaps integral with its walls at each end and with but one seam/that being preferably a corner overlap seam as indicated at i (Fig. 2), fastened by staples 2, or otherwise securely joined. This seam desirably extends along the longest dimension of the body, the flaps being at the ends because this calls for the least amount of waterproofing materials as will presently appear.

After the carton has received its contents, the

under f s 53 are first folded over; their proxmate may or may not be bridged over with tape, as desired, and if taped, any ordinary paper tape can be used. The top surfaces of these under flaps are then swabbed or coated with hot asphalt, as indicated at 4, with specially liberal application at each 'of the four carton corners, and the outer 4 flaps 5 are then folded over and pressed down onto .the under flaps so as to be stuck to them.

The asphalt referred to has the important characteristic that it is thin and fluid at 300 F., at which temperature it is applied, but after cooling is non-hardening and permanently sticky throughout the whole of the temperature range above referred to, and joints made or sealed with it do not become brittle or crack even at much lower temperatures. Asphalts of this kind are known on the market as steam-refined asphalts and are not expensive. They are described as havinga melting or softening point between 135 F. and 160 F. and a high penetration value which is preferably between 35 and 45 at 77 F., using a lOO-gram weight for five seconds. Similar sealing substances having these same properties, to the extent they are as cheaply obtainable, are obvious substitutes. The superposed flaps stick tightly after they have been'pressed together for the fewmoments required for ad vancing the carton to the next station in the asand most eflectively done by dipping the corner,

to a depth of about one inch or enough to cover the seam, in a bath of such asphalt, maintained at about .300 and therefore very fluid. This produces-what may be called a stripe coat covering the seam and sealing it, and is of fairly uniform width, as shown at 6 in Fig. 5. By providing the bath receptacle with a proper support, this operation is quickly accomplished by simply let- 5 ting the carton rest momentarily on the support with its corner submerged and then removing it. By the tme the corner-dipped carton reaches the next station in the line, the stripe coat will have cooled to near itsnormal condition of per- I 'manent tackiness, and in this condition a masking strip or tape 1 of tough, asphalt-impregnated even at elevated temperatures,

tively thin, tough paper, preferably about sixtypound Weight kraft paper, or thinner. The asphalt with which it is impregnated is a different grade from that used for sealing the flaps and corner seam, and produces an impregnated paper which is dry or non-sticky at all temperatures up to at least 135 F. Asphalt-impregnated paper sticks most tenaciously to any asphalt coating and is preferred on that account, but the same function would be to some degree obtained with any tough paper strip whether or' not asphalted. If the strip is cut longer than the seam, its ends are folded over onto the outer flap at each end, as indicated'in Fig. '5, and this endfolding is also desirable.

At the next station in the line the closed end of the carton, then appearing as in Fig. 6, is dipped mentioned, also maintained at about 300 F. and

to a depth of about 1 inches, although it could be deeper if preferred, thereby producing a dipped asphalt coating as indicated at 8 in Fig. 7. As soon as this coating has slightly cooled, a hood in the form of a rectangular paper sheet 9 and preferably of the same kind and grade of paper as the asphalt-impregnated tape 1, is applied to it and folded over it and over the end of the corner tape, .not only covering the whole dipped area 8 but with a liberal margin to spare all around. That is to say, the hood sheet 9 is pre-cut to a size enough greater than the dipcoated area so that its marginal portion II], for say, an average of an inch or so from its edges are not stuck to the body, although such portions may'lie against the body and appear to be adherent thereto. The hood folding is done by tucking the corners H under the folded flap l2, so that they are permanently secured in place by the adhesion of such folded flap l2 tov the sticky dip-coat beneath it. The operation just described is performed on both ends of the carton; thereby realizing the object of this invention as illustrated by Fig. 8 in its preferred form.

Such a carton, as already stated, has the advantages that it remains water-proof under water for at least as long as the fiber-board itself remains impervious, which is well over the two days prescribed, and that it does not become leaky as the result of being dropped, distorted by heavy pressure or subjected to any mechanical injury less than that which ruptures the fiber-board itself. Such packages can be hanate temperature and especially if under'pressure, I

as when the cartons are stacked. Such flow and .the attendant enlargement of the originally coated areas is accommodated under the free or unstuck portions or margins of the paper masking so that none of the asphalt can flow or creep to such an extent as tobecome exposed on the outer surface of the package to make it sticky,

There is, therefore, no opportunity for the stacked packages to stick together and be injured and rendered leaky by separation. In addition, this package, like other fiber packages, can be-opened with far less difiiculty than the metallic package which it substitutes.

While the asphalt sealing substance can be applied to the closed carton otherwise than as de- I scribed, the dipping method is preferred, first, because it insures a reliability and completeness of ensealment which would be diflicult to obtain with, for instance a brush, and second, because it lends itself to the production of stripe and hood coats with uniformly regular edges and of minimum area, thereby allowing for a more uniform overlap of the paper masking than could readily and rapidly be produced by other methods and conserving materials.

We claim:

1. A water-proof carton comprisinga body part formed of fiber-board containing in its composition sufficient sizing ingredient to be impervious to water for at least two days of submersion and folded to rectangular section with a longitudinal body seam and integral under and outer flaps folded over from the ends of the body walls in superposition to close the body, the outer flaps being adhesively united to their respective under flaps, and said folded-over sealed outer flaps and the portions of the body walls which immediately adjoin such folded-over flaps being dip-coated With a fusible non-hardening asphalt-like substance freely fluid at 300 F. and permanently sticky throughout normal atmospheric temperature range, and the body seam being likewise dipcoated with said substance and a masking applied dip-coated end portions of the carton, said strip and hood sheets being held to the carton solely by their adhesion to said coatings and being sufficiently larger than the coated areas to provide overlaps beyond-all the edges of said areas, capable of covering later enlargement of such areas occurring from pressure on the carton or from cold flow of the coatingsubstance. g

2. A water-proof-carton comprising a body part formed of fiber-board containing in its composition suflicient sizing ingredient to be impervious to water for at least two days of submersion and folded to rectangular section with a longitudinal body seam and integral under and outer flaps folded over from theends of the body walls'in superposition to close the body, the outer flaps being adhesively united and sealed to their respective under fiaps'by a fusible non-hardening asphalt-like substance freely fluid at 300 F. and permanently sticky throughout normal atmospheric temperature range, and said folded-over outer flaps and the adjoining marginal portions of the body walls being externally coated with said substance, and the body seam being likewise coated with said substance, and a masking applied to and covering all said coatings and held on the carton solely by sticking to such coatings and constituted of a strip of non-sticky paper covering the coated body seam with margins to spare on both sides, and hood sheets folded over the coated ends of the carton, also with margin to spare beyond the coated areas, whereby later enlargement of said coated areas can occur beneath the masking without becoming exposed.

' JAMES LARRIMORE. OTTO L. SCHELLER. STANLEY M. JACKSON. 

